The present invention relates to back flow preventers used to prevent contaminated water to flow through a hand spray mount.
Both the International Association of Plumbing and Mechanical Officials (IAMPO) and American Society of Mechanical Engineers (ASME) have issued standards mandating the use of backflow prevention apparatus with hand held hose-connected shower heads. These include of hose connection vacuum breakers and check valve which must be screwed in separately between the wall-mount water supply and the hose connection of the hand spray.
These prevent the back flow of dirty water into the clean water supply in the event that the hose-connected shower head hand spray is submerged when a vacuum in the supply plumbing is formed, as by draining of the supply pipes or a water hammer caused by other distant plumbing devices. Since it is important to prevent such contamination, the current units have tamper resistant non-removable features (such as break-away set screws) once installed.
However, since this interferes with drainage that may be required during maintenance or repair, the apparatus is further complicated with an additional drainage feature where required. In high-end plumbing fixtures, these mandated add-on backflow preventers detract from an aesthetically pleasing installation.
It is therefore an object of the present invention to provide a hand spray mount with integral backflow prevention.
It is also an object of the present invention to provide an aesthetically pleasing hand spray mount which utilizes a vacuum breaking air gap to prevent the accidental backflow of contaminated bath water through a shower hand spray to a clean water supply.
Other objects which become apparent from the following description of the present invention.
The wall mounts of this invention provide the normal hose connection for attachment of the hose of a hand-held spray head while integrating a IAMPO/ASME mandated backflow preventer in an aesthetically pleasing unit.
These wall mounts use two spring-biased check valves with an integral air inlet and check valve to form redundant backflow prevention as an active vacuum breaker, which would substitute ambient air for dirty water in the case of vacuum build-up. Because they are integrated in the housing of the wall mount that provides the hose connection, there is no way to disconnect the backflow prevention apparatus.
Normal plumbing tools are used for simple attachment or removal. Another feature of the wall mounts of this invention is the o-ring seal and set screw locking technique which permits exact set-up of the orientation and wall fit of the unit with simple tools.
An alternate embodiment of these wall mounts also integrates the hook which holds the handle of the hand-held spray head.